IQA _FAL - Fuzzy water quality index for lotic environments

ABSTRACT

The dissemination of information on water quality for a non-specialist audience is essential to support political and institutional actions for the management of aquatic environments. Therefore, water quality indices have been proposed since they are able to synthesize into a single value or category information, usually described from an extensive set of water quality variables. This research proposes a new water quality index, based on fuzzy logic, aimed at lotic environments, developed through the collaboration of experts in water quality of the Rio de Janeiro Environmental Agency (Instituto Estadual do Ambiente - INEA). The proposed index was applied to water quality data from the Paraíba do Sul River, obtained by INEA, in the years 2002 to 2009. The results of IQA_FAL showed that the index was able to synthesize the water quality of this stretch of the Paraíba do Sul, satisfactorily matching the assessments of the water quality assessments contained in the reports available. It was also noticed that with this methodology it was possible to avoid the attenuation of the influence of a variable in critical condition was attenuated by the influence of other variables in favorable conditions, producing an inaccurate result in the final index.

Keywords:
water quality index; fuzzy logic; lotic system; Paraíba do Sul River